Carriage lock for cutting or sawing machines



2 Sheets-Sheet l s. s. AUCHINCLOSS wnv ARRIAGE LOOK FOR CUTTING OR SAWING MACHINES 'Aug. 21, 1956 Filed Sept. 16, l953 INVEI ITO- SAMUEL S. AUCHINCLOSS BY z; Z

' ATTORNEY Aug. 21, 1956 s. s. AUCHINCLOSS ,50

CARRIAGE LOCK FOR CUTTING 0R SAWING MACHINES Filed Sept. 16, 1953 2 Sheet s-Sheet 2 INVENTOR SAMUEL S. AUCHINCL'OSS ATTORNEY United States Patent CARRIAGE LOCK FOR CUTTING OR SAWING MACHINES Samuel S. Auchincloss, Marietta, Pat, assignor to D eWalt Inc., Marietta, Pa'., a corporation of Pennsylvania Application September 16, 1953, Serial No. 380,433

8 Claims. (Cl. 143-47) This invention relates to carriage construction on reciprocating tool supporting machines. More particularly, it relates tosafety devices on such machines.

In the operation of sewing machines of the radial arm type, some danger is experienced" in that the cutting element may move inadvertently to the hazard of the operator. This is particularly so if the machine is not on a level floor, as for example, on shipboard. Heretofore, various devices have been used or suggested to overcome this ditficulty. Such a device is shown in the patent to Gardner et all, 2,297,882. There a form of ratchet and pawl is employed to lock the carriage against movement along the arm.

It is an object of this invention to devise an inexpensive, simple mechanism readily securable to the existant structure of the carriage and adequate to hold the carriage against movement when the same is released by the operator.

Another object of this invention is to construct a device of the type described that may be held in released position by slight pressure from the hand. of the operator..

It is a further object of this invention to device. a disc that may engage a surface on the radial arm to effect a braking action and at the same time be readily releasable by application of slight force. from the operator.

A still further object is to provide a releasable auto matic locking devicev associated-with a power driven tool which may be readily released to permit movement of the tool at an operators will.

In the accompanying drawings:

Fig. 1 is an end elevation, partly in section, of aradialarm saw supporting mechanismv in conjunction with a safety lock device in accordance with my invention-;.

Fig. 2 is a sectional side elevation of the saw supporting carriage also shown in conjunction with my safety device;

Fig. 3 is a sectional end elevation of a radialarm. supporting carriage in conjunction with a modified formv of my invention;

Fig. 4 is a sectional plan view illustrating the anchoring of the torsion spring. of the modified device, taken on line 4-l of Fig. 3;

Fig. 5 is a plan view of the radial arm supporting mechanism in conjunction with the modified safety device, and

Fig. 6 is a sectional plan view taken on line. 66: of Fig. 1, illustrating the. constructionof. the preferred form.

Referring now to the drawings,,l show (Figs. 1, Zand 6) a radial arm 10 having internal horizontal tracks 12- and oblique tracks 14 of the type shown. in patent to Knapp 2,185,304. The carriage I6 is. mounted. for iongitudinal movement along this arm by means of the horizontally mounted rollers 18 and the oblique rollers 20- engaging, respectively, track-s 12 and 14'.

A yoke 22 is. pivotally mountedbeneath the. carriage 16 on the vertical pivot pin 24-by means of lock nut 26. The pivot 24' carries the recess or recesses 23 engagedaby a key or set screw 25' (Fig. 35)) mounted in the yoke 22. Thus pivot 24 rotates with yoke. Yoke. 22 supports.

2:. motor and cutting tool indicated at 28.. Yoke 22' is held against rotational movement by the pin 30 mounted in the boss 32. Movement of the carriage 16 along the arm- 10 may be arrested by a screw member 34, the uses and purposes of which are clearly set forth in patent to Gardner et 211'. 2,289,259;

When the particular embodiment herein disclosed is employed, as for cross grain cutting, mitering or other operation. in which the work is held stationary and the saw moved. relative thereto, the operator moves the saw and carriage by grasping. the handle 36.

In the embodiment shown in Figs. 1,. 2 and 6, the pin 24 has a hollow bore tapped with a female thread in which is mounted a male member 38 having an integral. collar 40. A lock screw or nut 42-loose1y mounts thereon. the disc 44 having braking disc 45 secured by suitable means thereto. To the bottom of? the screw 38 is adjustably secured a lever 46 by means of the set screw 48. The free. end of the lever 46 is engaged by operating link 56 having on its free end push button 52. The link 50 passes through a bore 49 in yoke 22.. A compression spring 54 abuts a washer 53 seated in counterbore 51 and urges button 52 with link 50 to the right thereby rotating, through lever 46,. shaft 33 which by means of thread 39 moves upward to effect braking engagement between brake disc 56 and track 12' through disc 44. The operator while grasping the handle. 36. can. exert thumb pressure against the button 52' to overcome the thrust of spring 54.. This, of course, by means of members 50-, 46 and 38 releases the brake pressure on. the track 12.

Because of the mechanical. advantage of the lever 46 spring 54 need not exert great pressure. and accordingly its thrust may be overcome by the thumb of the operator on the button 52. Means (not shown) may be provided for adjusting t'ension, as for example threading. button 52 on link 50; It may be clearly seen by reference to Figs. 1 and 6 that the carriage I6 is locked against movement along the arm 10 unless the operator is actively engaging the button 52. When the operator releases the handle the spring 54" restores the parts to locking position as shownin Fig' 1.

It should be noted that when the yoke 2-2 is rotated, the link 50 rotates lever 46 and shaft 38. At the. same time, yoke 22 rotates pivot 24 by means of key or set screw 25 engaging a recess 23'. There is. therefore no relative movement between the engaging threaded portion of'shaf't 38 and pivot 24. During this rotation, the discs- 44 and 45 rotate on the collar 40 and remain in locked braking position with ttrack' 12.

In the embodiment illustrated in. Figs. 3,. 4 and 5, a torsion spring 154 is mounted about the male screw 138. Spring, 154' is anchoredin a. slot. of the head. of pivot 124 and inserts its other end 1.5411 (Fig. 4) in: the enlarged integral head of shaft 13$.v

Spring I54 supplants in function spring: 54. of the. first described embodiment. Spring 154 rotates the shaft 1:38 in the proper direction to urge it upwardly against the track 12 by means of threads (not shown) identical in structure to the threads 39 in. Fig. 1.

In this embodiment, leverage to overcome the torque of spring. 154 is provided by the lever 146 adjustably secured" to the bottom of. the shaft 138. by a set screw 148 as may be seenby reference. to- Figs; 3 and 5. The brake is released by pulling the. handle 152' preferably with the first and secondfingers. of the. operators hand holding handle 136. When. the operator releases the handle 136 locking action is. applied by torque spring 154' between disc and. track 1.2. As with the first: embodiment, the. entire mechanism rotates with yoke 22; The disc 144 rotates on shaftv 138: to remain in braking contact. with track 12.

It. is, of course, apparent that this invention may be applied with other carriage and bearing structures without departing from the teaching and intent of my invention, as set forth in the appended claims.

I claim:

1. In an apparatus of the character described, a hori zontally extending arm, a support for said arm, a carrier for a power-driven cutter, said carrier being secured to said arm for movement longitudinally thereof, a motor yoke provided with a pivot shaft to secure said yoke to said carrier, said yoke being provided with a handle for causing movement of the yoke on said pivot shaft, at least one longitudinal smooth track along said arm, said pivot shaft being keyed to said yoke and having a threaded bore therethrough, a plunger rotatably threaded into and through said bore, said plunger having at its one end a friction disc to engage said track on said arm, a lever adjustably secured to the other end of said plunger and operative to rotate said plunger to retract said disc from said track, means for yieldingly rotating said plunger to engage said disc against said track, and releasing means mounted on and rotatable with said yoke, said releasing means being connected to the free end of said lever and adapted to be actuated when said handle is gripped to release said friction member from said track whereby said carrier can be moved.

2. In an apparatus of the character described, a horizontally extending arm, a carrier secured to said arm for movement longitudinally thereof, a yoke for supporting a motor-driven rotatable cutting element pivotally secured to said carrier, said yoke being provided with a handle for causing movement of the carrier along said arm and rotating said yoke, a smooth track longitudinally formed along said arm, said yoke having a hole tapped therethrough at the center of its pivotal axis, a shaft threaded through said hole toward said track, a frictional member mounted on the end of said shaft toward said track so that rotation of said shaft in one direction will urge said frictional member against said track to arrest the movement of said carriage along said arm, yieldable means engaging said shaft to rotate it in said direction, and a lever engaging said shaft and mounted adjacent said handle operative to rotate said shaft in the opposite direction against said yieldable means to withdraw said frictional member from engagement with said track whereby an operator may release the frictional engagement of said member with said track during operation of the machine and it will automatically re-engage on removal of the operators hand.

3. In a machine of the type described having a horizontal arm, a carriage slidably mounted for movement along said arm, a tool supporting yoke secured to a vertical pivot beneath said carriage, said vertical pivot having a hollow threaded bore, means to secure said vertical pivot against rotational movement relative to said yoke, a threaded plunger threaded in said hollow bore of said pivot so that rotation in one direction moves said plunger longitudinally toward said arm, a friction member mounted on the end of said plunger adjacent said arm so that when said plunger is rotated to move longitudinally toward said arm said friction member is brought to bear against said arm to brake the movement of said carriage along said arm, yieldable means operatively mounted to rotate said plunger in one direction to move said plunger toward said arm, and means on said yoke moveable to engage said plunger to rotate it in the opposite direction against the action of said yieldable means and withdraw said braking force between said friction member and said arm whereby an operator may at will release said friction force and the rotation of said yoke with said pivot will not affect the braking action of said plunger.

4. In a machine of the type described having a horizontal arm, a carriage slidably mounted for movement along said arm, a tool supporting yoke secured to a vertical pivot beneath said carriage, said vertical pivot having a hollow threaded bore, means to secure said vertical pivot against rotational movement relative to said yoke,

a threaded plunger threaded in said hollow bore of said pivot so that rotation in one direction will move said plunger longitudinally toward said arm, a friction member mounted on the end of said plunger adjacent said arm so that when said plunger is rotated to move longitudinally toward said arm said friction member is brought to bear against said arm to brake the movement of said carriage along said arm, a lever secured to said plunger to rotate the same, a spring-loaded link pivoted to the free end of said lever to operate said lever to move said plunger longitudinally toward said horizontal arm to thrust said friction member with braking force against said arm, a button on said spring-loaded lever whereby it may be moved against the tension of its spring to rotate said plunger and friction member to a retracted position from said arm during operation of said machine whereby the release of said button automatically re-ensaid friction member against said arm.

5. In a machine tool having a horizontally disposed tool supporting arm, a tool supporting carriage slidably mounted for movement along said arm, a vertical pivot mounted for rotation in said carriage, said pivot having an axially threaded bore formed therein, a tool supporting yoke secured about and to said pivot, a threaded plunger mounted in the bore of said pivot, a frictional member on the upper end of said plunger adjacent said arm, said plunger being so constructed that rotation in one direction will move it longitudinally to bring said frictional member into braking contact with said arm, yieldable means secured to said yoke and engaging said plunger to rotate said plunger in said direction, and means to overcome the force of said yieldable means at will whereby said yoke may be rotated without efiecting any relative longitudinal movement of said plunger and said yieldable means can be overcome to move said plunger in a direction to release the braking pressure of said Eric tional member on said plunger against said horizontal arm.

6. In a machine tool having a horizontally disposed supporting arm, a tool supporting carriage slidably mounted on said arm for movement therealong, said carriage having a bore, a pivot engaging said bore, a tool secured to said pivot, said pivot having an axial opening, a shaft freely positioned in said opening, a frictional member on the end of said shaft adjacent said arm, said shaft being rotatable to bring said friction member in engagement with said arm, a torque spring mounted to rotate said shaft in the direction required to bring said friction member into engagement with said arm, a crank lever secured to said shaft whereby an operator may rotate said crank and said shaft in the opposite direction to withdraw said friction member from said arm.

7. In a machine of the type described having a horizontally disposed arm, a carriage longitudinally movable along said arm, a tool supporting yoke secured to said carriage about a vertical pivot, a handle on said yoke to move it and said carriage along said arm, said vertical pivot having a tapped bore therethrough, a threaded plunger threaded into said tapped bore, said plunger having a friction member secured to its one end adjacent said arm, a torque spring mounted about said plunger and anchored at its one end to said plunger and at its other end to said vertical pivot to rotate said plunger to urge its one end against said arm to form braking contact between said friction member and said arm, a lever secured to said plunger, a link supported adjacent said handle running from the free end of said lever and supported adjacent said handle so that the operator may move said lever to overcome the forces of said torque spring to release the braking contact between said friction member and said arm.

8. In a machine of the type described having a horizontal arm, a carriage slidably mounted for movement along said arm, a tool supporting yoke pivotally secured to a vertical pivot beneath said carriage, said vertical pivot having a hollow threaded bore, means to secure said vertical pivot against rotational movement relative to said yoke, a threaded plunger threaded in said hollow bore of said pivot so that rotation in one direction moves said plunger longitudinally toward said arm, a friction member mounted on the end of said plunger adjacent said arm so that when said plunger is rotated to move longitudinally toward said arm, said friction member is brought to bear against said arm to brake the movement of said carriage along said arm, and a torque spring mounted about said plunger to rotate it in one direction, said spring being anchored at its one end to said pivot and at its other end to said plunger means on said yoke engaging said plunger to rotate it in the opposite direction against the action of said spring and withdraw said braking force between said friction member and said arm whereby an operator may at will release said friction force and the rotation of said yoke with said pivot will not effect the braking action of said plunger.

Referenees Cited in the file of this patent UNITED STATES PATENTS 1,189,603 Michener July 4, 1916 1,550,520 Drucker Aug. 18, 1925 1,638,122 Jull Aug. 9, 1927 1,836,457 Emmons Dec. 15, 1931 2,185,304 Knapp Jan. 2, 1940 2,289,259 Gardner et al. July 2, 1942 2,297,882 Gardner et al. Oct. 6, 1942 2,590,093 Duerr Mar. 25, 1952 

